Cucumber-elderberry sparkler

Ingredients:

• 2 Iranian cucumbers
• Finely grated zest and juice of 1 lime
• 3/4 cup elderflower liqueur (such as St-Germain)
• Orange bitters
• 6-8 sugar cubes
• 1 bottle (750 ml) of champagne or other white sparkling wine, chilled

Preparation:

1. Grate the cucumbers coarsely. Wrap the grated cucumbers in a piece of cheesecloth or a clean kitchen towel and squeeze the cucumber juice into a pitcher; discard the remaining cucumbers. Stir in the lime zest and juice, elderflower liqueur, and 5-6 drops of orange bitters. Refrigerate until ready to serve, at least 30 minutes.
2. Drop a sugar cube into each champagne flute and add a few drops of orange bitters. Pour the champagne into the pitcher and stir. Pour the cocktail into the glasses.